27 



formed the marine acid. The mercury would be 

 necessarily forced up into the vessel by the pressure 

 of the external air. On examining the animals, I 

 found the bodies were corrodded. The fluid formed 

 on the surface of the mercury was the muriatic acid. 



EXPERIMENT VI. 



I obtained hydrogen gas from iron filings, by the 

 addition of the diluted sulphuric acid. Having intro- 

 duced it into the vessels, four worms were caused to 

 pass into it. They moved about a few minutes with 

 symptoms of pain, in the space of twenty minutes every 

 sign of life disappeared. They were then removed, 

 and the same means employed to revive them as in a 

 former experiment ; in ten minutes symptoms of life 

 returned, and in two hours they were so much revived 

 as to move with activity ; but never recovered their 

 health completely. 



I repeated the experiment with the same result. 

 Those that were permitted to remain in the gas four 

 hours could not be recovered by the same mode of 

 treatment. 



The inflammatory appearance which the parts near 

 the heads and the genital organs exhibited, after being 

 removed from the vessels in which they had been con- 

 fined, and exposed to the open air, induced me to sup- 

 pose that the change produced on the blood of the 



